title: Molecular characterization of trophic ecology within an island radiation of insect herbivores (Curculionidae: Entiminae: Cratopus).
abstract: The phytophagous beetle family Curculionidae is the most species-rich insect family known, with much of this diversity having been attributed to both co-evolution with food plants and host shifts at key points within the early evolutionary history of the group. Less well understood is the extent to which patterns of host use vary within or among related species, largely because of the technical difficulties associated with quantifying this. Here we develop a recently characterized molecular approach to quantify diet within and between two closely related species of weevil occurring primarily within dry forests on the island of Mauritius. Our aim is to quantify dietary variation across populations and assess adaptive and nonadaptive explanations for this and to characterize the nature of a trophic shift within an ecologically distinct population within one of the species. We find that our study species are polyphagous, consuming a much wider range of plants than would be suggested by the literature. Our data suggest that local diet variation is largely explained by food availability, and locally specialist populations consume food plants that are not phylogenetically novel, but do appear to represent a novel preference. Our results demonstrate the power of molecular methods to unambiguously quantify dietary variation across populations of insect herbivores, providing a valuable approach to understanding trophic interactions within and among local plant and insect herbivore communities.
authors.affiliation: School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.
authors.forename: James J N
authors.initials: JJ
authors.lastname: Kitson
authors.forename: Ben H
authors.initials: BH
authors.lastname: Warren
authors.forename: F B Vincent
authors.initials: FB
authors.lastname: Florens
authors.forename: Claudia
authors.initials: C
authors.lastname: Baider
authors.forename: Dominique
authors.initials: D
authors.lastname: Strasberg
authors.forename: Brent C
authors.initials: BC
authors.lastname: Emerson
mesh_terms: D000220:Adaptation, Biological / Q000235:genetics; D000818:Animals; D001499:Bayes Theorem; D002467:Cell Nucleus / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics; D004032:Diet; D004463:Ecology / Q000379:methods; D017753:Ecosystem; D014644:Genetic Variation; D005828:Genetics, Population; D006239:Haplotypes; D060434:Herbivory; D062312:Islands; D008436:Mauritius; D008969:Molecular Sequence Data; D010802:Phylogeny; D058974:Phylogeography; D017422:Sequence Analysis, DNA; D048889:Weevils / Q000235:genetics*
chemical_list: D004272:DNA, Mitochondrial
keywords: chloroplast; insect; plant; trophic ecology; weevil